1. Field of the Invention
The invention relates to a power tool attachment for beveling pipe ends. It is especially related to an attachment for a power tool in which the power tool saw can cut the end of a relatively large diameter pipe and the attachment can then immediately bevel the end of the cut pipe.
2. Description of Related Art
It is often desirable when assembling cut sections of pipe, particularly water supply pipes and sewage pipes, most relatively large thick walled plastic pipes, to form a beveled end on at least one end of the pipe sections to facilitate gluing operations or to facilitate sliding the pipe end into a bell housing having an internal ring-type seal. Beveling such pipes in the field is generally a tedious and time consuming task. It therefore becomes desirable to obtain a tool by which consistent and relatively precise angular bevels may be produced quickly and efficiently at the cut end of the pipe.
Portable pipe chamfering or beveling devices which are adaptable to power tools are known in the art. However, most of these devices are restricted for use on plastic pipes only or are hand held and operated devices with which only relatively thin wall plastic pipes can be beveled. Generally none of these devices can bevel steel or thick-walled plastic pipes because of the powering means used or the cutting tool incorporated being inadequate to cut such materials or for an operator to properly handle. In addition, none of the prior art attachments are adaptable to a circular power saw tool in such a way that the blade remains on the saw for cutting the end of the pipe and the attachments can then be used to bevel the pipe end. Of course, the present invention may be used on any rotary power tool, including drill, portable and fixed lathes, and similar power tools.
Known related art includes a pipe beveling attachment for a drill or router power tool as depicted in U.S. Pat. No. 4,180,358 to Uribe; a portable pipe end beveling tool characterized as a portable lathe and powered by an auxiliary power drive as depicted in U.S. Pat. No. 4,257,289 to Groothius; and a hand held and operated tool for beveling pipe or tube ends as depicted in U.S. Pat. No. 3,872,748 to Bjalme et al. and U.S. Pat. No. 5,641,253 to Wagner. Other known related portable pipe beveling tools include U.S. Pat. No. 5,853,272 to Wartluft et al., U.S. Pat. No. 4,586,408 to Goldner, U.S. Pat. No. 4,682,919 to Mitchell and U.S. Pat. No. 3,817,649 to Medney.
None of the devices in the above references solve the problem of providing a light weight, portable attachment for use in the field wherein the attachment is mounted to a rotary or circular power saw in which the saw blade can be used to cut off an end of a pipe and the pre-installed attachment can immediately be used to chamfer or bevel the pipe end, particularly, relative thick walled pipe. In addition, none of the devices can be used to cut and bevel either steel or plastic pipe.
In the industrial water supply and sewage pipe installation field, the current method used to bevel pipe, particularly plastic pipe, is to first cut the pipe with a circular or reciprocating saw. Then the bevel is done by taking a circular power saw and angularly positioning the blade and dragging the blade along the circumference of the pipe end to form a chamfer or bevel. This method exposes an individual to an extremely dangerous condition as the circular power saw is generally heavy and cumbersome to use and the blade could easily kick back and cut the individual's leg. To minimize the risk of injury, two people will often get involved by having one hold and rotate the end of the pipe while the other performs the beveling. Further, using a saw blade in this manner, that is, applying a lateral pressure on the blade, can cause the blade to fracture potentially placing an operator at a greater risk for injury. Therefore, the present invention is intended to enable a single individual to safely and efficiently cut and bevel the pipe end.
The current method of adding a bevel to a pipe requires skill and experience and is often performed by a foreman taking him away from other duties. At best, the beveling results in a non-uniform bevel. At worst, the bevel is cut at an incorrect angle on all or a portion of the pipe circumference and if unnoticed could result in a failure to seal properly. The present invention assures a properly cut bevel by a single individual with minimal training and experience. Further, there is no delay incurred between cutting the pipe to a specific length and beveling the end because no disassembly or reassembly of the attachment is required. In addition, no clamping of the attachment to the pipe end is required thereby allowing the operator to quickly chamfer or bevel the end of the pipe immediately after cutting the pipe with the blade. Fabrication time is saved and associated construction costs is reduced with the present invention.